The present invention relates to a chuck device for holding tool bits to a drive shaft of a power tool, and more particularly to a quick release chuck device incorporating a collet which is particularly useful on high speed devices, such as routers.
A typical conventional system used on portable stationary routers, laminate trimmers, dry wall cutters, etc., utilizes a collet tool holding device having a tapered collet that conforms to the hollow cone of the collet chuck or router motor shaft. Typically, a threaded nut is provided having a conical cam surface which matches the conical surface of the outer collet face. During operation of this type of device, the drive spindle or chuck of the machine tool must be held stationary in order to tighten the collet nut sufficiently. For this reason, most router chucks have, for example, spindle locks or are provided with an extra wrench that fits the chuck body or shaft. Similarly, to release the tool, the machine shaft or chuck body must be held stationary while the nut is loosened in the counterclockwise direction. This known conventional system has a number of drawbacks, for example, the tightening and loosening procedures have proven to be cumbersome and require a means, such as a separate wrench, for locking the spindle shaft. Also, with the conventional systems, the operator must physically tighten the nut onto the collet in very tight or close proximity to the sharp cutting edges of the tool bit carried by the collet.
Various attempts have been made in the art to provide an improved chuck device for high speed machine tools, particularly routers and the like. U.S. Pat. No. 5,511,801 issued to Kanaan et al., for example, provides a significant improvement in the art. The '801 patent discloses an integrated collet and chuck device which is actuated by turning a sleeve relative to a body member, with the sleeve having a nut fixed therein. The nut engages a screw member which is rotatably concentric within the nut. Rotation of the nut drives the screw member in the longitudinal direction and the screw member engages a collet thereby causing the collet to grip on a tool shank.
U.S. patent application Ser. No. 08/456,184, now abandoned, to Kanaan et al. discloses another quick release chuck device which is particularly useful on high speed tools. This device is actuated by a spring biased sleeve member which is moveable relative to a body member. Tapered pins are seated within tapered slots defined in the body member and contact and grip a tool shank inserted into the device in a spring biased position of the sleeve member.
U.S. Pat. No. 4,692,073 to Martindell describes a chuck apparatus for power bits utilizing a spring biased sleeve disposed about the drive spindle for axially securing the power bit to the chuck apparatus.
The present invention provides an improvement to the state of the art of quick release chuck devices utilizing a collet.